Class FieldSerializer<T, C extends FieldSerializerConfig>

java.lang.Object
com.esotericsoftware.kryo.Serializer<T>
com.esotericsoftware.kryo.serializers.FieldSerializer<T,C>
All Implemented Interfaces:
Comparator<FieldSerializer.CachedField>
Direct Known Subclasses:
CompatibleFieldSerializer, TaggedFieldSerializer, VersionFieldSerializer
public class FieldSerializer<T, C extends FieldSerializerConfig> extends Serializer<T> implements Comparator<FieldSerializer.CachedField>
Serializes objects using direct field assignment. FieldSerializer is generic and can serialize most classes without any configuration. It is efficient and writes only the field data, without any extra information. It does not support adding, removing, or changing the type of fields without invalidating previously serialized bytes. This can be acceptable in many situations, such as when sending data over a network, but may not be a good choice for long term data storage because the Java classes cannot evolve. Because FieldSerializer attempts to read and write non-public fields by default, it is important to evaluate each class that will be serialized. If fields are public, bytecode generation will be used instead of reflection.
See Also:

  • Field Details

  • Constructor Details

    • FieldSerializer

      public FieldSerializer(Kryo kryo, Class type)

    • FieldSerializer

      public FieldSerializer(Kryo kryo, Class type, Class[] generics)

    • FieldSerializer

      public FieldSerializer(Kryo kryo, Class type, Class[] generics, C config)

  • Method Details

    • rebuildCachedFields

      protected void rebuildCachedFields()
      Called when the list of cached fields must be rebuilt. This is done any time settings are changed that affect which fields will be used. It is called from the constructor for FieldSerializer, but not for subclasses. Subclasses must call this from their constructor.

    • rebuildCachedFields

      protected void rebuildCachedFields(boolean minorRebuild)
      Rebuilds the list of cached fields.
      Parameters:
      minorRebuild - if set, processing due to changes in generic type parameters will be optimized

    • buildValidFieldsFromCachedFields

      private List<Field> buildValidFieldsFromCachedFields(FieldSerializer.CachedField[] cachedFields, IntArray useAsm)

    • buildValidFields

      private List<Field> buildValidFields(boolean transientFields, List<Field> allFields, ObjectMap context, IntArray useAsm)

    • createCachedFields

      private void createCachedFields(IntArray useAsm, List<Field> validFields, List<FieldSerializer.CachedField> cachedFields, int baseIndex)

    • setGenerics

      public void setGenerics(Kryo kryo, Class[] generics)
      Description copied from class: Serializer
      Sets the generic types of the field or method this serializer will be used for on the next call to read or write. Subsequent calls to read and write must not use this generic type information. The default implementation does nothing. Subclasses may use the information provided to this method for more efficient serialization, eg to use the same type for all items in a list.
      Overrides:
      setGenerics in class Serializer<T>
      Parameters:
      generics - Some (but never all) elements may be null if there is no generic type information at that index.

    • getGenerics

      public Class[] getGenerics()
      Get generic type parameters of the class controlled by this serializer.
      Returns:
      generic type parameters or null, if there are none.

    • initializeCachedFields

      protected void initializeCachedFields()

    • newCachedField

      FieldSerializer.CachedField newCachedField(Field field, int fieldIndex, int accessIndex)

    • newMatchingCachedField

      FieldSerializer.CachedField newMatchingCachedField(Field field, int accessIndex, Class fieldClass, Type fieldGenericType, Class[] fieldGenerics)

    • getAsmFieldFactory

      private FieldSerializer.CachedFieldFactory getAsmFieldFactory()

    • getObjectFieldFactory

      private FieldSerializer.CachedFieldFactory getObjectFieldFactory()

    • compare

      public int compare(FieldSerializer.CachedField o1, FieldSerializer.CachedField o2)
      Specified by:
      compare in interface Comparator<T>

    • setFieldsCanBeNull

      public void setFieldsCanBeNull(boolean fieldsCanBeNull)
      Sets the default value for FieldSerializer.CachedField.setCanBeNull(boolean). Calling this method resets the cached fields.
      Parameters:
      fieldsCanBeNull - False if none of the fields are null. Saves 0-1 byte per field. True if it is not known (default).

    • setFieldsAsAccessible

      public void setFieldsAsAccessible(boolean setFieldsAsAccessible)
      Controls which fields are serialized. Calling this method resets the cached fields.
      Parameters:
      setFieldsAsAccessible - If true, all non-transient fields (inlcuding private fields) will be serialized and set as accessible if necessary (default). If false, only fields in the public API will be serialized.

    • setIgnoreSyntheticFields

      public void setIgnoreSyntheticFields(boolean ignoreSyntheticFields)
      Controls if synthetic fields are serialized. Default is true. Calling this method resets the cached fields.
      Parameters:
      ignoreSyntheticFields - If true, only non-synthetic fields will be serialized.

    • setFixedFieldTypes

      public void setFixedFieldTypes(boolean fixedFieldTypes)
      Sets the default value for FieldSerializer.CachedField.setClass(Class) to the field's declared type. This allows FieldSerializer to be more efficient, since it knows field values will not be a subclass of their declared type. Default is false. Calling this method resets the cached fields.

    • setCopyTransient

      public void setCopyTransient(boolean setCopyTransient)

    • setSerializeTransient

      public void setSerializeTransient(boolean setSerializeTransient)

    • setOptimizedGenerics

      public void setOptimizedGenerics(boolean setOptimizedGenerics)
      Controls if the serialization of generics should be optimized for smaller size.

      Important: This setting changes the serialized representation, so that data can be deserialized only with if this setting is the same as it was for serialization.

      Parameters:
      setOptimizedGenerics - If true, the serialization of generics will be optimize for smaller size (default: false)

    • write

      public void write(Kryo kryo, Output output, T object)
      This method can be called for different fields having the same type. Even though the raw type is the same, if the type is generic, it could happen that different concrete classes are used to instantiate it. Therefore, in case of different instantiation parameters, the fields analysis should be repeated. TODO: Cache serializer instances generated for a given set of generic parameters. Reuse it later instead of recomputing every time.
      Specified by:
      write in class Serializer<T>
      Parameters:
      object - May be null if Serializer.getAcceptsNull() is true.

    • read

      public T read(Kryo kryo, Input input, Class<T> type)
      Description copied from class: Serializer
      Reads bytes and returns a new object of the specified concrete type.

      Before Kryo can be used to read child objects, Kryo.reference(Object) must be called with the parent object to ensure it can be referenced by the child objects. Any serializer that uses Kryo to read a child object may need to be reentrant.

      This method should not be called directly, instead this serializer can be passed to Kryo read methods that accept a serialier.

      Specified by:
      read in class Serializer<T>
      Returns:
      May be null if Serializer.getAcceptsNull() is true.

    • create

      protected T create(Kryo kryo, Input input, Class<T> type)
      Used by read(Kryo, Input, Class) to create the new object. This can be overridden to customize object creation, eg to call a constructor with arguments. The default implementation uses Kryo.newInstance(Class).

    • getField

      public FieldSerializer.CachedField getField(String fieldName)
      Allows specific fields to be optimized.

    • getCachedFieldName

      protected String getCachedFieldName(FieldSerializer.CachedField cachedField)

    • removeField

      public void removeField(String fieldName)
      Removes a field so that it won't be serialized.

    • removeField

      public void removeField(FieldSerializer.CachedField removeField)
      Removes a field so that it won't be serialized.

    • getFields

      public FieldSerializer.CachedField[] getFields()
      Get all fields controlled by this FieldSerializer
      Returns:
      all fields controlled by this FieldSerializer

    • getTransientFields

      public FieldSerializer.CachedField[] getTransientFields()
      Get all transient fields controlled by this FieldSerializer
      Returns:
      all transient fields controlled by this FieldSerializer

    • getType

      public Class getType()

    • getKryo

      public Kryo getKryo()

    • getCopyTransient

      public boolean getCopyTransient()

    • getSerializeTransient

      public boolean getSerializeTransient()

    • createCopy

      protected T createCopy(Kryo kryo, T original)
      Used by copy(Kryo, Object) to create the new object. This can be overridden to customize object creation, eg to call a constructor with arguments. The default implementation uses Kryo.newInstance(Class).

    • copy

      public T copy(Kryo kryo, T original)
      Description copied from class: Serializer
      Returns a copy of the specified object. The default implementation returns the original if Serializer.isImmutable() is true, else throws KryoException. Subclasses should override this method if needed to support Kryo.copy(Object).

      Before Kryo can be used to copy child objects, Kryo.reference(Object) must be called with the copy to ensure it can be referenced by the child objects. Any serializer that uses Kryo to copy a child object may need to be reentrant.

      This method should not be called directly, instead this serializer can be passed to Kryo copy methods that accept a serialier.

      Overrides:
      copy in class Serializer<T>

    • getGenericsScope

      final Generics getGenericsScope()

    • getConfig

      public C getConfig()